Containers for storing and dispensing sterile liquids are known which have an inner or primary cap and an outer or overcap. Such containers are in common use for various medical and hospital procedures, such as the administration of irrigating solutions. An example of a prior art container is disclosed in Choksi U.S. Pat. No. 3,923,185.
Such sterile medical liquid containers have a common purpose of maintaining the sterility of their liquid contents during storage, shipping and dispensing. It is necessary that the closure system be easy for the nurse or physician to open, advantageously by the customary continuous counterclockwise rotation of the closure on the container.
The containers should be discarded after opening and use, and are commonly made of disposable thermoplastic material. Although the container disclosed in U.S. Pat. No. 3,923,185, mentioned above, may be discarded after opening and use, it is possible that it will be refilled and reused. By employing an internally threaded inner or primary cap which threadedly engages the externally threaded container neck, a nurse may reinstate the primary cap after refilling the container. Such refilling and reuse is generally considered undesirable and it is advantageous to have a disposable container system that prevents reuse instead of encouraging it.
Compressible materials, such as rubber, have frequently been used to provide the seals between the bottle and the closure; such compoundable materials form a mechanical seal which may be subjected to leaks as opposed to a welded or hermetic seal.